With the growth of the global population an‎d the need to reduce global warming an‎d air pollution, the use of renewable energies particularly geothermal energy, has increased. One application of this energy is in geotechnical structures such as energy piles, which serve both structural an‎d thermal exchange functions. Due to their thermo-mechanical behavior, energy piles are more complex than conventional piles an‎d are influenced by factors such as temperature changes, mechanical loading, an‎d soil type. In this study, the thermo-mechanical behavior of a thermal pile embedded in saturated san‎dy soil was investigated numerically using a 2D axisymmetric model in Abaqus/CAE 2021. The analysis process included three consecutive phases: heating the pile to 36°C over 12 days, cooling it to 17.5°C over 16 days, an‎d finally applying a mechanical load of 1300 kN at the pile head. In each stage, variations in vertical stress, strain, an‎d displacement were eva‎luated along the depth at three zones: the pile, the pile-soil interface, an‎d the surrounding soil. The effects of pile geometry were also examined by changing the radius (to 0.25 an‎d 1 m) an‎d depth (to 7.5 an‎d 20 m) compared to a reference pile (0.5×15 m). Results indicated that increasing temperature led to higher compressive stress an‎d expansion in the pile an‎d reduced settlement, while cooling caused increased contraction an‎d settlement an‎d reduced stress. Mechanical loading increased stress, displacement, an‎d settlement under both heating an‎d cooling. Increasing the pile radius enhanced heat transfer to the soil an‎d increased stress an‎d displacement, while reducing expansion. In contrast, increasing pile depth reduced heat transfer an‎d concentrated stress near the pile center, with higher expansion in deeper piles an‎d increased contraction in the surrounding soil. Overall, temperature, mechanical load, an‎d pile geometry significantly influence the thermo-mechanical behavior of energy piles

حميد هاشم الحسيني

محمدرضا خان محمدي , ميثم مشايخي